This invention relates to an improvement in the exercise shoe disclosed in U.S. Pat. No. 4,951,938 entitled EXERCISE SHOE, patented Aug. 28, 1990, Christopher J. B. Smith IV inventor and assigned to the same assignee as the present invention, and an improvement in the exercise shoe disclosed in design patent application Ser. No. 07/476,672, filed Feb. 8, 1990, entitled STRETCHING DEVICE FOR ROCKING THE FOOT TO STRETCH THE LOWER LEG, Christopher J. B. Smith IV inventor and assigned to the same assignee as the present invention; such exercise shoes are for sequentially stretching and strengthening various muscles and tendons in the lower legs and feet of a person; i.e. the person places a first foot on the exercise shoe and rocks the exercise shoe to stretch and strengthen various muscles and tendons in a first lower leg and foot and then the person places a second foot on the exercise shoe and rocks the exercise shoe to stretch and strengthen various muscles and tendons in a second lower leg and foot. More particularly, this invention relates to a pair of ganged exercise shoes of the type disclosed in the aforementioned patent and patent application and wherein various muscles and tendons in both lower legs and both feet of a person may be stretched and strengthened simultaneously or symmetrically.
The exercise shoe disclosed in the above-identified patent and patent application, particularly the patent application, is illustrated in FIGS. 1 and 2 and identified by general numerical designation 10. The exercise shoe 10 includes a generally semi-circular base 12 for engaging a support surface 14, e.g. a partially shown floor 14, on which the exercise shoe 10 rocks. The exercise shoe 10 further includes a support member 16 extending generally upwardly from the base 12 and heel and ball support platforms 18 and 20 for respectively receiving the heel and ball of the foot of a person, and as may be noted from FIG. 1, the heel and ball support platforms are disposed at an acute included angle .theta. with respect to each other. In use, or operation, a person places a first foot on the exercise shoe 10 with the heel of the person's foot residing on the heel platform 18 and with the ball of the person's foot residing on the ball platform 20, then, the person rocks the exercise shoe 10 alternately in the forward direction in the direction of the ball platform 10, and in the rearward direction in the direction of the heel platform 18. Upon the exercise shoe 10 being rocked in the forward direction, the plantar flexion occurs stretching and strengthening the interior flexor, i.e. the anterior tibialis and extensor digitorum longus and to some extent the plantar fascia of a first lower leg and first foot, and upon the exercise shoe 10 being rocked in the rearward direction, dorsiflexion occurs stretching and strengthening the plantar flexor, i.e. the gastrocnemius and soleus calf muscles, achilles tendon and plantar fascia of the first lower leg and first foot. The person then removes the first foot and places a second foot on the exercise shoe 10 and repeats the forward and rearward rocking motions.
The prior art exercise shoe 10, FIGS. 1 and 2, has proven quite successful in producing dorsiflexion and plantarflexion and in stretching and strengthening the above-noted lower leg and foot muscles and tendons of a person's lower leg and foot, one leg and one foot at a time. However, it has been observed that some people upon using the exercise shoe 10 to exercise one lower leg and one foot more than the other and thereby undesirably tend to stretch and strengthen the muscles and tendons of one lower leg and foot more than the other. This non-symmetrical or non-uniform stretching and strengthening of the various muscles and tendons of the lower legs and feet is due perhaps, at least in part, to the fact that most people in addition to being either righthanded or lefthanded are also right-sided or left-sided. Thus, a right-sided person tends to stretch and strengthen the lower right leg and right foot more than the lower left leg and left foot and a left-sided person, vice versa.
Accordingly, it has been found that there is a need in the exercise shoe art for exercise shoe apparatus which uniformly stretches and strengthens the above-noted muscles and tendons in both lower legs and both feet of a person symmetrically or uniformly or, viewed alternatively, which stretches and strengthens the above-noted muscles and tendons in both legs and both feet of a person simultaneously.